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Rare variable star 41 EP

Algol

RA 47.0422° · Dec 40.9556° · star

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Score breakdown

· 8 badges
41 pts · Rare
Rare 50 pts → Epic
  • Naked-eye visible +8
  • Has a proper name +8
  • Hot blue B-type star +6
  • Variable star +5
  • Blue-white star +5
  • Gently variable +4
  • A named variable star +3
  • Main-sequence star +2
Total score 41

9 more points to reach Epic.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • Has a proper name · +8
  • Hot blue B-type star · +6
  • Main-sequence star · +2
  • Blue-white star · +5
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B8V — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
  • Where it is in life. It is on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.
  • It changes. This star does not hold still: its brightness rises and falls on a rhythm of hours, days or years, either pulsing in size or being eclipsed by a companion.

Sense of scale

  • In perspective. Inside our stellar backyard: every radio broadcast humanity has ever made has already swept past it.

Find it in the sky

  • How to spot it. At magnitude 2.1 you can see it with your own eyes from a dark site, over in Perseus.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • Best time of year. It stands highest in the middle of the night around November — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Properties

absmag
-0.112
bv
-0.003
constellation
Per
dist ly
89.9245
luminosity
96.5606
mag
2.09
name
Algol
named
yes
spect
B8V
var amplitude
0.14
var designation
Bet
var max
2.073
var min
2.213

About Algol

Algol is a rare variable star. It lies about 89.9 light-years from Earth, sits in the constellation Per, shines at apparent magnitude 2.09 and has spectral type B8V.

Its spectrum reads B8V — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

Look for Algol in the constellation Per. At apparent magnitude 2.09, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, Algol is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why Algol is a rare variable star

Algol scores 41 points on Spacedle's rarity scale, which places it in the rare tier. Another 9 points would lift it into a rarer tier.

That score comes from 8 science badges — Variable star, Naked-eye visible, Has a proper name, Hot blue B-type star, Main-sequence star, Blue-white star, Gently variable and A named variable star — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.